Urgent need exists for developing next-generation clinical diagnostics devices for screening individuals exposed to and/or intoxicated with biological threat agents. These devices need to be rapid, sensitive, and capable of detecting both presymptomatic and symptomatic markers for specific diagnosis to enable effective countermeasures including therapeutic intervention. Such systems must also be easy-to-use, automated and self-contained, and preferably, have a small footprint to allow use in point-of-care and point- of-incident settings. We propose to develop a portable device for screening individuals potentially exposed to biological toxins. The device will perform rapid microfluidic chip-based immunoassays (<3-10 minutes) with low sample volume requirements (10 uL) and appreciable sensitivity (nM-fM). Our microfluidic method facilitates hands- free analysis by integrating sample pretreatment (filtering, enrichment, mixing) with electrophoretic immunoassays to quickly measure analyte concentrations in minimally pretreated bodily fluids. The microfluidic chip is integrated with miniaturized electronics, optical elements such as diode lasers, fluid- handling components, data acquisition software, and a user interface to create a portable, self-contained device. The device is capable of detecting presymptomatic and symptomatic biomarkers of exposure to multiple toxins simultaneously (up to 32 analytes per chip). The device has potential for triaging, identifying exposure mode and severity and directing or monitoring countermeasures including treatment. Validation will involve testing of exogenous human serum and mucus samples as well as samples from animals intoxicated with selected toxins. Technologies and intellectual properties developed will be transferred to a commercial partner for pilot-scale manufacturing of the device. We will also implement a product development plan with our commercial partner to initiate preparation for obtaining regulatory clearance. The diagnostic device and methods can also be extended to detection of biomarkers of other systemic diseases and conditions such as cancer and cardiovascular disease.